class CommonUtil:
    def check_file_type(self, ext):
        """判断是图片还是视频"""
        if ext in ['.mpo', '.tif', '.heic', '.webp', '.tiff', '.jpeg', '.dng', '.pfm', '.jpg', '.png', '.bmp']:
            return 'image'
        elif ext in ['.m4v', '.wmv', '.webm', '.gif', '.mkv', '.asf', '.avi', '.mov', '.mp4', '.mpg', '.mpeg', '.ts']:
            return 'video'
        return 'unknown'
